Seasonal groups of Japanese anchovy Engraulis japonicus caught in coastal waters off Yamaguchi Prefecture, southwestern Sea of Japan
2017
Kawano, M.
Seasonal groups of Japanese anchovy Engraulis japonicus caught in coastal waters off Yamaguchi Prefecture in 2015 were discerned based on the monthly body size compositions and the daily ages. Middle-sized (40-70 mm BL) group appeared during May to August and made a peak of catch in July. After September small-sized (25-45 mm BL) group occurred instead of the middle-sized one. Daily age analyses revealed that the former group hatched March to June (spring) and the latter group hatched July to November (summer-autumn). Comparing the seasonal groups between during the years of 1968-1973 (high stock level period) and in 2015 (low stock level period), the author found that winterhatched group and large-sized spring hatched group which had appeared during 1968-1973 were not found in 2015, and the small sized group occurred from September in 2015, one month faster than those during 1968-1973.
Показать больше [+] Меньше [-]